Contribution To Literature:

The PARTNER 2A trial showed that TAVR is noninferior to SAVR for the primary endpoint at 2 years for the treatment of severe aortic stenosis in intermediate-risk patients (STS-PROM 4-8%; median 5.8%).

Description:

The goal of the trial was to assess the safety and efficacy of balloon-expandable transcatheter aortic valve replacement (TAVR) compared with surgical aortic valve replacement (SAVR) in intermediate-risk patients.

Study Design

Patients were stratified in cohorts according to access route (transfemoral [76.3%] or transthoracic) and were then randomly assigned (in a 1:1 ratio) to undergo either TAVR (n = 1,011) or SAVR (n = 1,021). TAVR was performed with the balloon-expandable TAVR XT valve system.

Any therapeutic invasive cardiac procedure resulting in a permanent implant that is performed within 30 days of the index procedure (unless part of planned strategy for treatment of concomitant coronary artery disease)

Any patient with a balloon valvuloplasty (BAV) within 30 days of the procedure (unless BAV is a bridge to procedure after a qualifying echocardiogram)

Interpretation:

The results of this trial indicate that TAVR with the second-generation Sapien XT valve is noninferior to SAVR for the primary endpoint of mortality/disabling stroke at 2 years for the treatment of severe symptomatic aortic stenosis in intermediate-risk patients (STS PROM score 4-8%; median 5.8%). Transfemoral TAVR was possible in about 75% of the patients, and in these patients, TAVR appeared to be superior to SAVR. Vascular complications were higher in TAVR patients at 30 days, while new-onset atrial fibrillation, acute kidney injury, and bleeding were higher in the SAVR arm. Valve performance at 2 years was similar between the two strategies, although moderate to severe PVL was significantly higher in the TAVR arm at 2 years. From the patient’s perspective, transfemoral TAVR provided earlier symptomatic benefit; this was comparable to surgery at 2 years of follow-up.

Although upfront costs were higher with TAVR with both Sapien XT and S3 valves (driven by THV valve cost of ~$32,500 compared with ~$5,000 for surgical valves), a TAVR strategy saved $9-10K per patient over 1 year of follow-up, being highly cost-effective and perhaps even cost-dominant. Results between TAVR and SAVR were sustained out to 5 years, including for valve gradients; moderate to severe PVL continued to be higher with TAVR (using second-generation Sapien XT valve).

This is a landmark trial in this field and resulted in approval for intermediate-risk patients. The higher PVL rate with TAVR is an important limitation, although the Sapien device currently commercially available is the third-generation S3 valve (as compared with the second-generation XT valve studied in this trial), which has a skirt around the valve frame specifically to reduce the incidence of this complication. Further long-term data from the S3 cohort of the PARTNER 2 trial also are awaited.